Superfamily Castoroidea Gray 1821 (rodent)
Parent taxon: Castorimorpha according to L. Doronina et al. 2017
See also McKenna and Bell 1997 and Montgelard et al. 2002
Sister taxa: Castoridae, Geomyidae, Geomyoidea, Heteromyidae
Subtaxa: Eutypomyidae
Ecology: ground dwelling herbivore
Distribution:
• Arikareean of United States (5: Mississippi, Montana, Oregon collections)
• Oligocene of Canada (2: Saskatchewan), United States (16: Florida, Nebraska, North Dakota, Oregon, South Dakota)
• Eocene to Oligocene of United States (1: Nebraska)
• Eocene of Canada (7: Saskatchewan), United States (19: Colorado, Montana, Nebraska, North Dakota, South Dakota, Texas, Utah, Wyoming)
Total: 50 collections including 53 occurrences